Thanks to getting the fragment, Juggernaut is more powerful yet more vulnerable as well. Spidey's punches will get more effect and you can actually throw Juggie in some instances.

Watch out for his opening attack. He'll do a giant leap which aftermath is a big outward wave of rocks and debris that you have to jump clear of. He may do a few different actions after but wait until he pounds the ground before you go in close. You'll only have a one second or so window to get a hit in, so keep within jumping distance of Juggie, evading backwards if he comes towards you. And when he pounds the ground, jump over the wave of rocks and hold X to come crashing down on him. Finish with a couple of Y button presses and leap away. Repeat.

You'll soon whittle him down enough where Juggie will scream to the rafters and leap up yet again. This time he'll do it twice so avoid the wave each time. Then make sure to jump away to avoid his rush to your last known position.

Juggernaut will then start pounding the ground in frustration hard enough to rain a cloud of debris and dust. Once he stops pounding, use that dust as cover to get behind him and hit him with X. The B button icon will immediately appear above his head, so follow that prompt to twirl ol' Juggie into a wall.

Juggernaut will start throwing objects at you with a vengeance. But after each throw, Juggie will sag a bit from the effort. Use that moment to jump until he's highlighted in red and B kick him. Hold B so as to finish the zipline and get a few X hits in (Y's too slow), then jump back and up to avoid his followup shockwave attack. Repeat.

If by chance you miss Juggie and throw a piece of debris at him instead, don't sweat it (you still hurt him, after all ;>). Just jump away and try again next throw.

Juggernaut's next scream of anger will prompt 3 leaps. Avoid and jump out of the way like before. This time when he throws however, act faster. Instead of a shockwave, Juggernaut will usually follow up with a homing rush which shockwave can really catch you offguard.

So either immediately B kick him after his throw or stay in the air as jumping up is the best way to avoid damage (since jumping to the side may still leave you in the shockwave's blast area).

This time after his leap and pound dust up, a simple X will send him toppling down. And you win yourself another fragment!